Method of connecting one or more contactless components to a single antenna, and corresponding system

Abstract

A first component (CMP 1 ) is connected to the antenna (ANT) and to an impedance matching circuit (CAI) configurable on command and connected to the antenna, and in the absence of another component (CMP 2 ) connected to the antenna, the impedance matching circuit is placed in a first configuration in which it forms with the first component and the antenna a resonant circuit having a first resonant frequency compatible with a carrier frequency. In the presence of a second component (CMP 2 ) connected to the antenna, the impedance matching circuit is placed in a second configuration in which it forms with the first component, the second component and the antenna a resonant circuit having a second resonant frequency compatible with the carrier frequency.

That which is claimed: 
     
       1. An electronic device comprising:
 an antenna having first and second terminals; 
 a first irremovable component coupled to the antenna and configured to communicate via the antenna according to a first contactless-type communication protocol; 
 a second removable component configured to couple to the antenna and communicate according to a second contactless-type communication protocol; 
 an impedance matching circuit comprising a first capacitor having a first electrode coupled to the first terminal of the antenna and a second electrode coupled to the second terminal of the antenna, a second capacitor having a first electrode coupled to the first electrode of the first capacitor and a second electrode, and a third capacitor having a first electrode coupled to the second electrode of the first capacitor and a second electrode; and 
 a controllable activation component coupled between the second electrode of the second capacitor and the second electrode of the third capacitor and configured to define a first configuration state of the impedance matching circuit formed by the first, second and third capacitors when the second removable component is not coupled to the antenna, and a second configuration state of the impedance matching circuit when the second removable component is coupled to the antenna and the second and third capacitors are disabled from the impedance matching circuit. 
 
     
     
       2. The electronic device according to  claim 1 , wherein the first configuration state defines a resonant circuit between the first irremovable component and the antenna having a resonant frequency compatible with a carrier frequency. 
     
     
       3. The electronic device according to  claim 1 , wherein the second configuration state defines a resonant circuit between the second removable component and the antenna having a resonant frequency compatible with a carrier frequency. 
     
     
       4. The electronic device according to  claim 1 , further comprising an interface configured to couple the second removable component to the antenna. 
     
     
       5. The electronic device according to  claim 1 , further comprising a controller coupled to the controllable activation component to select one of the first and second configuration states. 
     
     
       6. The electronic device according to  claim 1 , wherein the controllable activation component comprises at least one MOS transistor. 
     
     
       7. The electronic device according to  claim 1 , wherein the controllable activation component comprises a pair of MOS transistors. 
     
     
       8. The electronic device according to  claim 1 , wherein the first irremovable component comprises a Near Field Communication (NFC) compatible component. 
     
     
       9. The electronic device according to  claim 8 , wherein the antenna comprises an NFC antenna. 
     
     
       10. An electronic device comprising:
 an antenna; 
 a first irremovable component coupled to the antenna and configured to communicate via the antenna according to a first contactless-type communication protocol; 
 a second removable component configured to couple to the antenna and communicate according to a second contactless-type communication protocol; 
 an impedance matching circuit comprising first, second and third capacitors; and 
 a controllable activation component configured to define a first configuration state of the impedance matching circuit formed by the first, second and third capacitors when the second removable component is not coupled to the antenna, and a second configuration state of the impedance matching circuit when the second removable component is coupled to the antenna and the second and third capacitors are disabled from the impedance matching circuit. 
 
     
     
       11. The electronic device according to  claim 10 , wherein the first configuration state defines a resonant circuit between the first irremovable component and the antenna having a resonant frequency compatible with a carrier frequency. 
     
     
       12. The electronic device according to  claim 10 , wherein the second configuration state defines a resonant circuit between the second removable component and the antenna having a resonant frequency compatible with a carrier frequency. 
     
     
       13. The electronic device according to  claim 10 , further comprising an interface configured to couple the second removable component to the antenna. 
     
     
       14. The electronic device according to  claim 10 , further comprising a controller coupled to the controllable activation component to select one of the first and second configuration states. 
     
     
       15. The electronic device according to  claim 10 , wherein the controllable activation component comprises at least one MOS transistor. 
     
     
       16. The electronic device according to  claim 10 , wherein the controllable activation component comprises a pair of MOS transistors. 
     
     
       17. The electronic device according to  claim 10 , wherein the first irremovable component comprises a Near Field Communication (NFC) compatible component. 
     
     
       18. The electronic device according to  claim 17 , wherein the antenna comprises an NFC antenna. 
     
     
       19. A method of configuring an impedance matching circuit coupled to an antenna for contactless-type communication, the impedance matching circuit comprising first, second and third capacitors, the method comprising:
 coupling a first irremovable component to the antenna and to the impedance matching circuit; 
 selectively coupling a second removable component to the antenna and the impedance matching network; and 
 operating a controllable activation component to define a first configuration state of the impedance matching circuit formed by the first, second and third capacitors when the second removable component is not coupled to the antenna, and to define a second configuration state of the impedance matching circuit when the second removable component is coupled to the antenna and the second and third capacitors are disabled from the impedance matching circuit. 
 
     
     
       20. The method according to  claim 19 , wherein the first configuration state defines a resonant circuit between the first irremovable component and the antenna having a resonant frequency compatible with a carrier frequency. 
     
     
       21. The method according to  claim 19 , wherein the second configuration state defines a resonant circuit between the second removable component and the antenna having a resonant frequency compatible with a carrier frequency. 
     
     
       22. The method according to  claim 19 , wherein the first irremovable component comprises a Near Field Communication (NFC) compatible component. 
     
     
       23. The method according to  claim 22 , wherein the antenna comprises an NFC antenna.